Pen



FIG. 1 is a top, right, front perspective view of a pen in accordance with my design;

FIG. 2 is a bottom, front, right perspective view thereof;

FIG. 3 is a rear elevational view thereof;

FIG. 4 is a right side elevational view thereof, with the left side elevational view being a mirror image thereof;

FIG. 5 is a front elevational view thereof;

FIG. 6 is a right side elevational view thereof shown with the two parts of the design being separated for clarity; and,

FIG. 7 is a front elevational view thereof shown with the two parts of the design separated for clarity. 

CLAIM The ornamental design for a pen, as shown and described. 